438 research outputs found
Exploiting quantum parallelism of entanglement for a complete experimental quantum characterization of a single qubit device
We present the first full experimental quantum tomographic characterization
of a single-qubit device achieved with a single entangled input state. The
entangled input state plays the role of all possible input states in quantum
parallel on the tested device. The method can be trivially extended to any
n-qubits device by just replicating the whole experimental setup n times.Comment: 4 pages in revtex4 with 4 eps figure
Periastron shift in Weyl class spacetimes
The periastron position advance for geodesic motion in axially symmetric
solutions of the Einstein field equations belonging to the Weyl class of vacuum
solutions is investigated. Explicit examples corresponding to either static
solutions (single Chazy-Curzon, Schwarzschild and a pair of them), or
stationary solution (single rotating Chazy-Curzon and Kerr black hole) are
discussed. The results are then applied to the case of S2-SgrA binary
system of which the periastron position advance will be soon measured with a
great accuracy.Comment: To appear on General Relativity and Gravitation, vol. 37, 200
On Proper Polynomial Maps of
Two proper polynomial maps are said to be \emph{equivalent} if there exist such that .
We investigate proper polynomial maps of arbitrary topological degree up to equivalence. Under the further assumption that the maps are Galois
coverings we also provide the complete description of equivalence classes. This
widely extends previous results obtained by Lamy in the case .Comment: 15 pages. Final version, to appear in Journal of Geometric Analysi
Trait interactions effects on tropical tree demography depend on the environmental context
Although functional traits are defined based on their impact on demographic parameters, trait-demography relationships are often reported as weak. These weak relationships might be due to disregarding trait interactions and environmental contexts, which should modulate species trait-demography relationships. We applied different models, including boosted regression tree (BRT) models, to investigate changes in the relationship between traits and demographic rates of tropical tree species in plots along an elevational gradient and among time intervals between censuses, analyzing the effect of a strong drought event. Based on a large dataset of 18,000 tree individuals from 133 common species, distributed among twelve 1-ha plots (habitats) in the Atlantic Forest (Brazil), we evaluated how trait interactions and the environmental context influence the demographic rates (growth, mortality, and recruitment). Functional traits, trait-trait, and trait-habitat interactions predicted demography with a good fit through either BRTs or linear mixed-models. Changes in growth rates were best related to size (diameter), and mortality rates to habitats, while changes in recruitment rates were best related to the specific leaf area. Moreover, the influence of traits differed among time intervals, and for demographic parameters, habitat affected growth and mortality by interacting with diameter. Here, we provide evidence that trait-demography relationships can be improved when considering the environmental context (space and time) and trait interactions to cope with the complexity of changes in the demography of tropical tree communities. Thus, to expand predictions of demography based on functional traits, we show that it is useful to fully incorporate the concept of multiple trait-fitness optima, resulting from trait interactions in different habitats and growth conditions.We thank the Brazilian National Research Council (CNPq) and the Coordination for the Improvement of Higher Education Personnel (CAPES) for the scholarships conceded to the first author (CNPq 141781/2016-5 and CAPES 88881.189491/2018-01) and for the productivity fellowship to FAMS (CNPq 310168/2018-0). This study was financed by research funding of the projects: âFunctional Gradientâ (Biota/FAPESP 03/12595-7), âPELD/BIOTAâ and âECOFORâ (Processes 2012/51509-8 and 2012/51872-5, within the BIOTA/FAPESP Program), âEcoSpaceâ (Edital Universal CNPq 459941/2014-3), âSustainable Landscapes Brazilâ project (US Forest Service, USAID, US Department of State and EMBRAPA), and âSustainable Landscapesâ (NASA-Goddard). This study was also supported by CNPq (PELD CNPq 403710/2012-0), British Natural Environment Research Council/NERC (NE/K016431/1) and FAPESP as part of a doctoral fellowship (FAPESP 11/11604-0). CPC was financed by the Estonian Research Council (PSG293)
On the Completeness of the Set of Classical W-Algebras Obtained from DS Reductions
We clarify the notion of the DS --- generalized Drinfeld-Sokolov ---
reduction approach to classical -algebras. We first strengthen an
earlier theorem which showed that an embedding can be associated to every DS reduction. We then use the fact that a
\W-algebra must have a quasi-primary basis to derive severe restrictions on
the possible reductions corresponding to a given embedding. In the
known DS reductions found to date, for which the \W-algebras are denoted by
-algebras and are called canonical, the
quasi-primary basis corresponds to the highest weights of the . Here we
find some examples of noncanonical DS reductions leading to \W-algebras which
are direct products of -algebras and `free field'
algebras with conformal weights . We also show
that if the conformal weights of the generators of a -algebra
obtained from DS reduction are nonnegative (which isComment: 48 pages, plain TeX, BONN-HE-93-14, DIAS-STP-93-0
Mineralogical, petrographic and chemical analyses for the study of the canvas "Cristo alla Colonna" from Cosenza, Italy : a case study
A multi-technique study on materials used for the painting "Cristo alla Colonna" by Luigi Bria (private collection, Cosenza, Italy) was carried out for the first time during the restoration plan. Pigments, binder media and raw materials used for the application of ground and priming layers were studied using optical (OM) and electronic microscopy equipped with energy dispersive spectroscopy qualitative microanalysis (SEM-EDS), infrared spectroscopy (FTIR) and gas chromatography coupled with mass spectrometry (GC/MS). The goal of this study was to characterize this canvas and to set up a scientific aid and guide for its restoration, taking into account the, severe damage not exclusively due to natural decay processes. Our data can provide information about historical and stylistic background as well as advises for correct planning of the cleaning procedures. Riassunto - II dipinto su tela "Cristo alla Colonna", opera di Luigi Bria (collezione privata, Cosenza, Italia), \ue8 stato sottoposto, durante le fasi di restauro, per la prima volta ad indagine strumentale tramite varie tecniche analitiche. I pigmenti, i leganti ed altri materiali utilizzati per la sua realizzazione sono stati analizzati tramite microscopia ottica (OM), microscopia elettronica e microanalisi tramite spettrometria a dispersione di energia (SEM-EDS), spettroscopia infrarossa (FTIR) e gascromatografia accoppiata spettrometria di massa (CG/MS). Lo scopo del lavoro \ue8 stato quello di offrire una caratterizzazione dell'opera pittorica, nonch\ue9 fornire un supporto scientifico ad un un corretto intervento di restauro su un'opera fortemente degradata. I risultati hanno permesso di fornire informazioni di natura storico-artistico nonch\ue9 informazioni utili ad un corretto intervento di pulitura della tela oggetto di questo studio
A Note on Domain Walls and the Parameter Space of N=1 Gauge Theories
We study the spectrum of BPS domain walls within the parameter space of N=1
U(N) gauge theories with adjoint matter and a cubic superpotential. Using a low
energy description obtained by compactifying the theory on R^3 x S^1, we
examine the wall spectrum by combining direct calculations at special points in
the parameter space with insight drawn from the leading order potential between
minimal walls, i.e those interpolating between adjacent vacua. We show that the
multiplicity of composite BPS walls -- as characterised by the CFIV index --
exhibits discontinuities on marginal stability curves within the parameter
space of the maximally confining branch. The structure of these marginal
stability curves for large N appears tied to certain singularities within the
matrix model description of the confining vacua.Comment: 33 pages, LaTeX, 6 eps figures; v2: references adde
The Vega debris disc: A view from Herschel
We present five band imaging of the Vega debris disc obtained using the Herschel Space Observatory. These data span a wavelength range of 70-500 mu m with full-width half-maximum angular resolutions of 5.6-36.9 ''. The disc is well resolved in all bands, with the ring structure visible at 70 and 160 mu m. Radial profiles of the disc surface brightness are produced, and a disc radius of 11 '' (similar to 85AU) is determined. The disc is seen to have a smooth structure thoughout the entire wavelength range, suggesting that the disc is in a steady state, rather than being an ephemeral structure caused by the recent collision of two large planetesimals
Virgin olive oil and health: summary of the III international conference on virgin olive oil and health consensus report, JAEN (Spain) 2018
The Mediterranean diet is considered as the foremost dietary regimen and its adoption is associated with the prevention of degenerative diseases and an extended longevity. The preeminent features of the Mediterranean diet have been agreed upon and the consumption of olive oil stands out as the most peculiar one. Indeed, the use of olive oil as the nearly exclusive dietary fat is what mostly characterizes the Mediterranean area. Plenty of epidemiological studies have correlated that the consumption of olive oil was associated with better overall health. Indeed, extra virgin olive oil contains (poly)phenolic compounds that are being actively investigated for their purported biological and pharma-nutritional properties. On 18 and 19 May 2018, several experts convened in Jaen (Spain) to discuss the most recent research on the benefits of olive oil and its components. We reported a summary of that meeting (reviewing several topics related to olive oil, not limited to health) and concluded that substantial evidence is accruing to support the widespread opinion that extra virgin olive oil should, indeed, be the fat of choice when it comes to human health and sustainable agronomy
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